Although PD-L1 expression may correlate with responses to their inhibitors, the studies are plagued by a lack of uniformity in methodology of staining assessment, the antibody used and cutoff values for positivity.[37] Consequently, there is substantial debate regarding utilization of PD-L1 expression as a biomarker[37] and there are conflicting results regarding its prognostic influence in resected NSCLC.[4, 39–41] The two largest studies published to date [41, 42] suggest PD-L1 expression is associated with improved prognosis but have significant limitations. The gene discussed is CD274; the disease is non-small cell lung carcinoma.